It's too hard for me to setup Outlook and Thunderbird to get my yahoo mail, so i jut go to the webpage. I've always used web-based mail. Since I opened my e-mail account back in 1997. It's still the account I use today.
I've always used Hotmail, ever since I was younger, and I still do (albeit with a live.com.au address now). The only thing is, is that I tried out Windows Live Mail Desktop (the first name) when it was released and haven't looked back for a while now.
It sits comfortably close to Firefox on my taskbar and I never have to reload, wait for all the JavaScript and whatnot to load.
I might consider using a web-based client again because of things like App Tabs, but ehhhhh.